1. Field of the Invention
This invention relates to filler presses and electrolyzers, having respectively a plurality of plates for separating solids from liquids or a plurality of plate-like cells including a pair of anode and cathode compartments facing each other with an ion exchange membrane therebetween. More specifically the invention is directed to apparatus for assuring that a stack of plates or cells are precisely positioned with respect to a press/cell follower and head piece and are adequately sealed to prevent leakage.
2. Statement of Art
Prior art filter presses such as seen in U.S. Pat. Nos. 4,107,042; 4,364,827; and 4,806,239 all show presses which utilize a fixed head piece and a follower with a stack of plates therebetween where a hydraulic ram arrangement drives the follower against an end plate of the stack to move all the plates in the stack into engagement. The handles of plates normally slide on a pair of side slide rails or the plates are suspended from and movable on an overhead rail(s). Various pawl and piston arrangements mounted in a carriage have been proposed to shift individual ones or groups of plates in the stack for subsequent discharge of cake accumulated on filter media surfaces on the plates during the filtration cycle, and thereafter for washing the filter media surfaces on individual plates preparatory to another filtering cycle. In the case of electrolyzers a series of cell frames typically with a height of 1.2 meters and a width of 2.4 meters form a plate. Each plate is bisected by a metal partition wall forming anode and cathode compartments. Each compartment has an electrolyte inlet and an electrolyte and gas outlets, and an ion exchange membrane is installed between each anode compartment and cathode compartment. Handles are attached to each cell frame in order to hang the frames typically on side rails of a head and follower press. Due to the corrosive nature of the various materials being filtered, the electrolytes used and gasses emitted from the operation of the electrolyzer, it has been necessary to have special seals and the like on the plates and cell frames to prevent egress of corrosive or other harmful unsafe products from the plate or cell press. Further, specifically in the case of the electrolyzer the ion exchange membrane between the cell frames is highly sensitive to a uniform sealing pressure. The press industry has generally relied on the use of precise rail surfaces and handle surfaces along with a center activated follower to insure a fair degree of alignment of the plates or cells with or without special edge sealing of the plates or cell frames with respect to one another. Despite these constructions it has been found that the plates and cell frames are difficult to align in parallelism since one or more plates or cell frames can become canted during movement of the follower to close the stack of plates or cell frames or cumulative manufacturing errors can cause misalignment.